TM 5-4220-211-12&P
FUEL SYSTEM/GOVERNOR
d.
Clamp off fuel supply line from tank to injection pump.
e.
Remove Allen plug and from injection pump with 5mm Allen wrench.
f.
Install drip pipe, copper washers and banjo bolt into injection pump with 14mm wrench.
g.
Open fuel line to allow fuel to flow to injection pump.
h.
Set compression release pin to neutral position. This is the first "click" of the compression release, usually 10
o'clock.
i.
Rotate flywheel counter clockwise until fuel flows freely from drip pipe.
j.
Continue turning flywheel counter clockwise until fuel stops dripping. Slowly continue to rotate flywheel
counter clockwise. When the fuel starts to drip from the fuel pipe, STOP. Hold the flywheel in that position and check the
timing marks on flywheel and engine housing.
NOTE
Summary explanation of fuel flown during timing. Check while
turning flywheel counter clockwise.
(1)
Fuel will flow freely.
(2)
Fuel will drip from pipe.
(3)
Fuel flow will stop.
(4)
Fuel will again start to drip. At this point you hold the flywheel on this position and check the timing.
k. Using a metric rule, measure the distance between the two marks. Check the timing chart for the correct
RPM and the (mm) distance before top-dead-center.
l.
See timing change procedure for complete instructions. Add or remove shims as needed to obtain proper
timing.
m. Reinstall injection pump to engine and check for proper timing. Note: As a general rule-of thumb, to change
from 3600 RPM to 3000 RPM, add one shim .2mm (approx. .008) to the existing shims behind the injection pump. Adding
.2mm shim behind the pump will retard the timing. To increase timing one would remove shims from the engine.
A-7.
ENGINE SPEED GOVERNING SYSTEM. The governor uses centrifugal force to limit engine speed. As engine
speed increases, the two governor flyweights are forced further and further apart. This pushes the governor pin outward
against the tappet bolt surface, causing the governor lever to push the pump rack towards its idling position. Unopposed,
this would simply return the engine to an idle. However, when the throttle lever is moved, the part or full throttle, the
throttle shaft extension screw moves away from the governor lever extension. This allows the spring on the inside end of
the throttle shaft to constantly pull the pump rack towards it full open position. The point at which these two forces balance
determines maximum engine speed at any throttle setting. It's now easy to see how the governor maintains engine speed
under changing loads. When a load is applied or increased, the engine slows and the flyweights move closer together.
This permits the governor lever to move the pump rack towards the full open position until again stopped by the governor
pin.
A-8.
GOVERNOR ADJUSTMENT. Open governor inspection cover using a screwdriver, remove one screw from the
governor inspection cover and slide the plate away. Put the speed control lever in the top speed position. With a small
screwdriver, pry away the locking tab from the governor lock nut. Loosen the lock nut with a 10mm open end wrench.
Turn the flywheel until the governor weights are split at the vertical position. With a standard screwdriver, speed the
weights as far as they will go. With the governor weights spread to the maximum, using a small screwdriver, screw in the
adjusting screw until it just contacts the governor pin. Release the screwdriver from the weights, and screw the adjusting
screw an additional 1/2 turn. Keeping the screwdriver into the slot, tighten up the lock nut. Then bend the locking tab over
the lock nut. Reinstall the cover.
A-25
